Plate for plate heat exchangers



Nov. 26, 1957 P. HYTTE 2,814,469

PLATE FOR PLATE HEAT EXCHANGERS Filed Oct. 19. 1954 2 Sheets-Sheet 1 Fig.1

INVENTOR.

For: us [arsson Wylie BY ATTOR NE Y5 Nov. 26, 1957 Filed Oct. 19, 1954 P. L. HYTTE PLATE FOR PLATE HEAT EXCHANGERS 2 Sheets-Sheet 2 INVENTOR.

Panius farsson q/yfle ATTORN E Y5 United States Patent PLATE FOR PLATE HEAT EXCHANGERS Pontus Larsson Hytte, Ljunghusen, Sweden, assignor to Aktiebolaget Separator, Stockholm, Sweden, a corporation of Sweden Application October 19, 1954, Serial No. 463,251

Claims priority, application Sweden October 29, 1953 Claims. (Cl. 257-245) This invention relates to plate heat exchangers and particularly to an improved heat exchange plate of the type which is provided along its edge with a tightening or sealing rib of elastic material attached to the plate.

In plate heat exchangers, the individual plates are usually provided with a marginal packing consisting of tightening or sealing ribs of rubber or a similar elastic material, which are fitted in depressed grooves. When the plates are compressed together, each tightening rib is pressed against the outer edge of the groove with considerable force, so that unless some counter-measure is taken the outer edge is apt to be deformed and the groove opened, whereby the sealing ability of the tightening rib ceases and leakage occurs. To prevent this, one expedient heretofore used is to increase the thickness of the sheet material of the plates so that they can adequately resist the deforming forces. In reality, however, this means that the plates must be made thicker than is necessary or desirable from other points of view. Thus, an increase in the thickness of the plates increases the price of the apparatus, not only because of the added cost of the individual plates but also because a greater number of plates is required due to the impaired heat transmission of the individual plates. Moreover, a plate apparatus provided with thick plates requires more space and becomes much heavier than an apparatus having thin plates.

The present invention has for its principal object the provision of an improved heat exchange plate which overcomes the above-mentioned inconveniences. This object is attained mainly by providing the plate, outside the sealing rib, with a supporting and stiffening device for the sealing rib, this device being arranged so that the plate is supported by the sealing ribs lying next to the plate. The supporting and stiffening device is preferably so arranged that it receives pressure from the sealing rib of its corresponding plate and is also supported, preferably to about the same degree, by the sealing rib of an adjacent plate. For this purpose, the supporting and stiffening device of each plate should be located on both sides of a plane parallel to the plate and disposed exactly or approximately half-way between its sealing rib and the adjacent sealing rib of a plate which lies next to this plate.

For a better understanding of the invention, reference may be had to the accompanying drawings in which:

Referring to Fig. 1 of the drawings, the series of heat exchanger embodying plates made according to the invention, the section being taken at a right angle to the marginal packing and the adjoining parts of the plates, and

Figs. 2 through 10 are similar views of modified forms of the plates, the frame part of the exchanger being omitted.

Referring to Fig l of the drawings, the series of heat exchange plates 1 is shown as containing only three plates for the sake of simplicity, it being understood that substantially more than this number will generally be used. The plates 1 can be provided in the usual manner with 2,814,469 Patented Nov. 26, 1957 transverse corrugations 2 of suitable form, and with supporting bosses 3. The sealing or tightening ribs are shown at 4, these ribs being made of rubber or other elastic material and extending along the plates near their marginal edges. The supporting and stiffening means 5 are shown in the form of ribs secured in any suitable manner to the marginal portions of the plates outside the sealing ribs 4, as by means of spot-welding 6. The ribs 5 are made of a rigid material, such as metal, and each of these ribs is confined to only one side of the respective plate. At its marginal portion, each plate 1 is bent to form an offset seat for its rib 5, so that the latter is located on both sides of a plane 7 which is parallel to the plate and which, in the case of a plate other than an end plate of the series, lies half-way between the sealing rib 4 of the plate and the adjacent sealing rib 4 lying next to this same plate. Thus, the supporting and stiffening means 5 on each plate 1 (other than an end plate) receives pressure from both of these sealing ribs. The frame parts for holding the plate pack are shown at 8 and 9 in Fig. 1.

As shown in Fig. 2, the supporting and stiffening means are in the form of ribs 5a which, as in the Fig. l embodiment, are secured to offset seats of the plates and at only one side of the respective plates. in the Fig. 2 embodiment, the ribs 5a comprise sheet metal strips which are bent so that a portion of the cross-section of each rib 5a forms an angle with the plane of the plate, whereby the plate is further stiffened.

Referring now to Figs. 3 to 6, the supporting and stiffening means there shown consist of ribs or sheet metal strips arranged along the plate edge on both sides of the plate. In these embodiments the marginal portion of the plate is not bent from the main plane of the plate as in Figs. 1 and 2. According to Fig. 3, two stiffening ribs 5b are secured by welding 6 to opposite sides of the plate. According to Figs. 4 to 6, the stiffening ribs are constituted by sheet metal strips 5c, 5d and 5e, respectively, which are bent over so as to embrace the edges of the plates. In the arrangements according to Figs. 5 and 6, the sheet metal strips 5d and 5e, moreover, are each bent in the same way as the rib 5a in Fig. 2, so that a portion of its cross-section forms an angle with the plane of the plate to stiffen it further.

In the embodiments shown in Figs. 7 to 9, the supporting and stiffening means 5 5g and 5h, respectively, are each formed by bending over the marginal portion of the plate to form a hollow profile. As shown in Fig. 8, this hollow profile 5g is further reinforced by a filling rib 10 of metal inserted therein. The edge of the plate is bent inward and may be secured by welding, as indicated at 11 in Figs. 8 and 9. The cross-section of the supporting and stiffening means 512 in Pig. 9 is partly bent at an angle to the main plane of the plate, whereby further stiffening of the plate is obtained.

The embodiment shown in Fig. 10 differs from the arrangement according to Fig. 1 in that the ribs 51' in Fig. 10 are provided with inwardly projecting thin springs 12 by means of which the ribs are fixed to the plates 1 by spot-welding 6, or the like. The springs 12 may be formed in any suitable manner, as by milling. By shaping the supporting and stiffening means in this way, the risk of the plate buckling, when the rib is secured, is reduced, whereby any subsequent straightening of the plates can be dispensed with.

It will be observed from the foregoing that the supporting and stiffening device for the sealing rib may be wholly or partly integral with the heat exchange plate or may consist of or include a part which is Welded or otherwise secured to the plate. In the following claims, the expression fixed to the plate is intended to apply to any of these conditions.

I claim:

1. In a heat exchange plate, the combination of an elastic sealing rib extending along the edge portion of the plate, and a supporting and stitfening device for the sealing rib fixed to the plate outside said rib, said device forming rib-supporting surfaces at opposite sides of the main plane of the plate and extending at an angle to said plane, one of said surfaces engaging said rib and the other surface being engageable with the adjacent sealing rib of a similar adjacent plate, whereby said device is adapted to support said first plate by the ribs.

2. In a plate heat exchanger, the combination of a pack of heat exchange plates, elastic sealing ribs extending along the edge portions of the respective plates, and a device on each plate for supporting and stiffening the corresponding sealing rib and fixed to the plate outside said rib, said device being located on both sides of a plane parallel to the plate and which is disposed about half-way between the corresponding sealing rib and the adjacent sealing rib of an adjacent plate, whereby said device is positioned laterally from both of said ribs, said device forming rib-supporting surfaces extending at an angle to said plane at both sides thereof and engaging the rib of the corresponding plate as well as the rib of said adjacent plate.

3. The combination according to claim 2, in which said device is symmetrically arranged with respect to said plane.

4. The combination according to claim 2, in which said device includes a marginal part of the plate which is bent back upon itself.

5. The combination according to claim 2, in which said device forms a hollow profile at the edge of the plate.

6. The combination according to claim 2, in which said device includes a rib secured to the plate.

7. The combination according to claim 2, in which said device includes ribs disposed on both sides of the plate.

8. The combination according to claim 2, in which said device i cludes a strip which is bent over and embraces the edge of the plate and is secured to the plate.

9. The combination according to claim 2, in which said device has a part forming a stiffening marginal portion of the plate extending at an angle to the adjacent part of the plate.

10. The combination according to claim 2, in which said device forms a hollow profile at the edge of the plate, and comprising also a filling rib in the hollow of said profile.

References Cited in the file of this patent FOREIGN PATENTS 64,182 Denmark Dec. 3, 1945 67,709 Denmark Sept. 13, 1948 95,642 Sweden May 9, 1939 580,368 Great Britain Sept. 6, 1946 681,176 Germany Sept. 16, 1939 714,330 Germany Nov. 27, 1941 

